He sang badly, out of turn (5)
I believe the answer is:
angus
'he' is the definition.
'sang badly out of turn' is the wordplay.
'badly' is an anagram indicator (letters in the wrong order).
'out of' is an insertion indicator (some letters on the outside of others).
'turn' becomes 'u' (a 'U-turn' is a kind of turn).
'sang' with letters rearranged gives 'angs'.
'angs' going around 'u' is 'ANGUS'.
(Other definitions for angus that I've seen before include "Scotsman" , "Former Scottish county" , "Aberdeen . . . . ., breed of cattle" , "Scots man's name" , "Scot" .)